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On Weather Stations and Climate Trends

There’s been an ongoing attack on the credibility of federal climate monitoring efforts that has been partly inspired by Anthony Watts. In 2007, Mr. Watts, a former TV weather forecaster, began recruiting legions of volunteers across the United States to inspect the thousands of weather stations — some in people’s back yards or in parking lots — that have for generations produced the raw data feeding into federal and independent efforts to track climate trends. The result was SurfaceStations.org. Its rogues gallery of photos of particularly suspect weather stations has been credited by many meteorologists and climatologists as a wake-up call for the need for better monitoring (an issue that affects many other realms, from monitoring acid rain to tracking flood risks):

The revelations fueled charges that all that asphalt and the like was inflating temperature estimates and thus conclusions that the nation’s climate was warming over all. One result was Mr. Watts’ far more popular blog, Watts Up With That, which has arguably become the dominant pipeline for any news or commentary challenging conclusions that greenhouse gases could dangerously disrupt climate.

Now, though, a new study by Matthew Menne and other scientists at the National Climatic Data Center, the federal office charged with tracking climate trends, directly challenges the underpinnings of arguments that Bad Weather Stations = Faulty Climate Conclusions. In essence, the paper, On the Reliability of the U.S. Surface Temperature Record (pdf), concludes that the instrument issues, as long acknowledged, are real, but the poor stations tend to have a slight cool bias, not a warm one.

The findings are robust enough that a frequent critic of climate overstatement, Chip Knappenberger, has provisionally endorsed the findings and thrown cold water on the idea that bad weather stations undercut the picture of a warming continent.

I’ve seen a lot of Anthony Watts’ presentations and pictures of poorly sited thermometers, but never an analysis to conclusively show that there is a warm bias in the adjusted U.S. temperature record as a result. Yes, many sites are poorly situated and the temperature they read is impacted by things other than the larger-scale weather — but also, such things are being corrected for (or at least an attempt is being made to correct for them) by the various producers of a U.S. temperature history (i.e. Menne et al. at NCDC). So, while the raw data are undoubtedly a mixture of climate and non-climatic influences, the adjusted data presumably have more of a climate signal. The recent paper by Menne et al., seems to bear this out. Anthony Watts and colleagues, no doubt have an analysis of their own in the works. It’ll be interesting to see what their results show. The results from Menne et al. suggest that while a picture may be worth a thousand words, it is the data which actually tells the story. I await a formal analysis from Watts et al. and the story that it may tell.

I consulted Mr. Watts and with David Easterling at the National Climatic Data Center, who supervises the researchers who wrote the new paper, to get added perspective on the new paper. Here’s what they had to say:

Dr. Easterling of the climate center said, among other things, that Mr. Watts had been invited to participate in writing the paper, given that it drew on his weather-station data. “We invited him a number of times to participate in the work,” he said. “He declined.” Dr. Easterling said that the new analysis shows that the adjustments that are made to account for shifting patterns of climate-data collection (the same adjustments are among the targets of those challenging global warming evidence) are robust.

“I don’t want to disparage Watts,” Dr. Easterling added. “He did do us a service by highlighting the fact there are a lot of issues with some of these stations. We are trying to address these issues.” He said that, going forward, the evolving Climate Reference Network will largely eliminate the need for such adjustments in any case.

In addition, he wrote the following long note, in which he contradicts Dr. Easterling’s description of the exchanges between the federal center and Mr. Watts over participation in the paper. In it, he says a rebuttal is in the works. Stay tuned.

From Anthony Watts:

The appearance of the Menne et al paper was a bit of a surprise, since I had been offered collaboration by NCDC’s director in the fall. In typed letter on 9/22/09 Tom Karl wrote:
“We at NOAA/NCDC seek a way forward to cooperate with you, and are interested in joint scientific inquiry. When more or better information is available, we will reanalyze and compare and contrast the results.”

“If working together cooperatively is of interest to you, please let us know.”

I discussed it with Dr. Pielke and the rest of the team, which took some time since not all were available due to travel and other obligations. It was decided to take up NCDC on a collaboration offer.

On November 10, 2009, I sent a reply letter via Federal Express to Mr. Karl, advising him of this. In that letter I also reiterated my concerns about use of the preliminary data (43% surveyed), and spelled out very specific reasons why.

We all waited, but there was no reply from NCDC to our reply to offer of collaboration by Mr. Karl from his last letter.

Then we discovered that Menne et al had submitted a paper to JGR Atmospheres using my preliminary data and it was in press. This was a shock to me since I was told it was normal procedure for the person who gathered the primary data the paper was based on to have some input in the review process. Pielke concurs as you know.

NCDC uses data from one of the largest volunteer organization in the world, the NOAA Cooperative Observer Network. Yet NCDC director Karl, by not bothering to reply to our letter about an offer he initiated, and by not giving me any review process opportunity, extends professional discourtesy to my own volunteers and my team’s work.

==============

I’ll point out that NCDC threw up a roadblock early on in the project, one that required a legal argument to overcome.

To interest volunteers, we had to publish imagery of what had been found so far, as a way to garner interest. With no funding, there was no other option, this is why social networking was employed.
Within two weeks of that announcement on Pielke’s blog of the project starting, on or about 6/24/07 NCDC removed information which had been previously publicly available on their station metadatabase.

Given the timing, (five days later after Mr. Karl’s e-mail below), it is now seen as an attempt to thwart the SurfaceStations project. Mr. Karl comments to colleagues in an e-mail about the project:

From: “Thomas.R.Karl”
To: Phil Jones

Subject: Re: FW: retraction request
Date: Tue, 19 Jun 2007 08:21:57 -0400
Cc: Wei-Chyung Wang
Thanks Phil,
We R now responding to a former TV weather forecaster who has got press, He has a
Web site of 40 of the USHCN stations showing less than ideal exposure. He claims he can
show urban biases and exposure biases.
We are writing a response for our Public Affairs. Not sure how it will play out.
Regards, Tom

Clearly Mr. Karl viewed the SurfaceStations project as a threat, as this e-mail coincides with the timing of portions of the public metadata disappearing. A week later, after launching some legal arguments against NCDC, they relented and restored access, which I documented here.

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As for the Menne paper itself, I’m rather disturbed by their use of preliminary data at 43 percent, especially since I warned them that the data set they had lifted from my Web site (placed for volunteers to track what had been surveyed, never intended for analysis) had not been quality controlled at the time. Plus there’s really not enough good stations with enough spatial distribution at that sample size. They used it anyway, and amazingly, conducted their own secondary survey of those stations, comparing it to my non-quality-controlled data, implying that my data wasn’t up to par. Well of course it wasn’t! I told them about it and why it wasn’t. We had to resurvey and rerate a number of stations from early in the project. This came about only because it took many volunteers some time to learn how to properly ID them. Even some small towns have 2-3 COOP stations nearby, and only one of them is USHCN. There’s no flag in the NCDC database that says “USHCN”, in fact many volunteers were not even aware of their own station status. Nobody ever bothered to tell them. You’d think if their stations were part of a special subset, somebody at NOAA/NCDC would notify the COOP volunteer so they would have a higher diligence level?

If doing a stations survey was important enough for NCDC to do to compare to my data now for their paper, why didn’t they just do it in the first place?

We currently have 87 percent of the network surveyed (1067 stations out of 1221), and it is quality controlled and checked. I feel that we have enough of the better and urban stations to solve the “low-hanging fruit” problem of the earlier portion of the project. Data at 87 percent looks a lot different than data at 43 percent.

The paper I’m writing with Dr. Pielke and others will make use of this better data, and we also use a different procedure for analysis than what NCDC used.

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Menne mentioned a “counterintuitive” cooling trend in some portions of the data. Interestingly enough, former California State climatologist James Goodridge did an independent analysis of COOP stations in California that had gone through modernization, switching from Stevenson Screens with mercury LIG thermometers to MMTS electronic thermometers. He writes:

Hi Anthony, I found 58 temperature station in California with data for 1949 to 2008 and where the thermometers had been changed to MMTS and the earlier parts were liquid in glass. The average for the earlier part was 59.17°F and the MMTS fraction averaged 60.07°F.
Jim

A 0.9°F (0.5°C) warmer offset due to modernization is significant, yet NCDC insists that the MMTS units are tested at about 0.05 cooler. I believe they add this adjustment into the final data. Our experience shows the exact opposite should be done and with a greater magnitude. I can provide Jim’s contact info if interested.

When our paper is completed (and hopefully accepted in a journal), we’ll let science do the comparison on data and methods, and we’ll see how it works out. Could I be wrong? Quite possibly. But everything I’ve seen so far tells me I’m on the right track.

Anthony

The ball is clearly in Mr. Watts’s court. The peer-reviewed literature awaits.

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By 2050 or so, the human population is expected to pass nine billion. Those billions will be seeking food, water and other resources on a planet where humans are already shaping climate and the web of life. Dot Earth was created by Andrew Revkin in October 2007 -- in part with support from a John Simon Guggenheim Fellowship -- to explore ways to balance human needs and the planet's limits.